Answer:
The answer is C)
Explanation:
The predators were unable to keep the population of the mussels down. The mussels took more area of the rock. Other species that needed space did not return to the tidal pool. Otters can also be keystone species as they eat urchins. By doing so, they prevent the sea urchins form eating all the kelp plants and removing the entire habitat for many other species. The Keystone Species theory shows that this impact of few predators, that made up a minor amount of the total species, could have such a high impact on the ecosystem.
Answer:
1
Explanation:
The rest are wrong b/c it helped <em>expand</em> China rather than isolate it, they didn't use ships on the Silk Road, and it brought better communications, etc. between countries.
The answer is faults because when divergent boundaries occur, the tectonic plates move away from each other, therefor creating a fault in the earths crust.
Answer:
Most beaches get their sand from rocks on land. Over time, rain, ice, wind, heat, cold, and even plants and animals break rock into smaller pieces. This weathering may begin with large boulders that break into smaller rocks. Water running through cracks erodes the rock.
Density, because the core is made of metals like iron and nickel
